NASA’s tough choice: Starliner’s mission vs astronauts’ wellbeing?

NASA officials held a news conference on Wednesday (August 7) to discuss how the ongoing issues with Boeing’s Starliner spacecraft could impact the forthcoming SpaceX astronaut flight to the International Space Station. Notably, there was no representative from Boeing present at the meeting.

Since its first astronaut mission, Starliner has encountered several challenges, particularly when five out of its 28 reaction control system (RCS) thrusters failed to work properly during docking with the ISS on June 6. NASA announced on Tuesday (August 6) that work on the issue was still in progress, which means the next launch to the ISS will be delayed.

UPDATES ON CREW-9 MISSION TO THE ISS

SpaceX’s ninth mission to the International Space Station, Crew-9, has been rescheduled to launch on September 24 instead of August 18. This mission is meant for four astronauts. NASA is considering sending only two astronauts on the Crew-9 mission and bringing back two Starliner astronauts with them around February 2025.

TEST FLIGHT TURNS EXTENDED INTO STAY

The Crew Flight Test mission (CFT), which launched on June 5, included NASA astronauts Butch Wilmore and Sunita 
Williams. They were chosen for their experience as former US Navy test pilots. Originally planned for a 10-day mission, the duo has now been in space for over 60 days and the mission is ongoing.

NASA is stressing that the astronauts can leave the International Space Station (ISS) in case of an emergency. However, it is now less sure about whether the astronauts will return home using the Starliner, as originally planned.

EXPERTS GRAPPLING WITH UNCERTAINTIES

Ken Bowersox, associate administrator for NASA’s space operations and a former astronaut, mentioned during a briefing that they now have multiple options. According to Space.com, they are not limited to using the Starliner to bring crew back; they can choose another spacecraft, if necessary.

The alternative vehicle could be SpaceX. The main issue is figuring out how problems with the Starliner’s thrusters might impact its ability to undock and return to Earth. Some NASA experts believe that the return to Earth may put a strain on the RCS thrusters again. Not everyone is on the same page about the possible cause. CFT engineers have suggested that overheating in the ‘doghouse’ shelters—enclosures that protect the RCS thrusters—may be causing the insulation around the thrusters to come off.

In ground testing, one of the poppet valves—a type of valve used to control the flow of liquids or gases which opens and closes by moving up and down, like a lid on a jar, to allow or block the flow—in Starliner’s thrusters has been experiencing issues. According to Steve Stich, NASA’s commercial crew program manager, the valve has been “heating up, pushing out and then shrinking back”. Additionally, there has been some noticeable damage to the insulation. This information was reported by Space.com.

SAFETY FIRST, OR MISSION ACCOMPLISHED?

Different members of NASA’s program control board have varying opinions on what is causing the thruster problems and how much risk these issues pose to the astronauts. Stich described the situation as both a physics and reliability issue. The exact behaviour of the RCS thrusters, including any lingering effects from insulation shedding or poppet valve issues, has not been fully understood despite extensive testing.

Stich mentioned that Starliner can still safely detach from the ISS, but there is uncertainty about how its thrusters will perform during the return trip. Stich stated that understanding why the RCS and the poppet valve are behaving this way would increase their confidence in moving forward with returning Butch and Suni on this spacecraft. He also mentioned that NASA has reached out to propulsion experts from other divisions, like the Jet Propulsion Laboratory, to see if they can identify anything that Boeing and NASA’s CFT engineers may have overlooked during thorough ground and space testing.

If the program control board cannot agree and no clear data emerges, the decision about Starliner’s flight will be made by Bowersox, who has been given the authority by NASA administrator Bill Nelson. Ultimately, the final decision lies with Nelson.

Nelson was on the last space shuttle flight just 10 days before the Challenger disaster in 1986, narrowly escaping the tragedy. He has openly discussed how deeply the event affected him. The Challenger disaster occurred when the shuttle exploded shortly after liftoff, resulting in the loss of all seven crew.

NASA TO ADJUST CREW-9 ASSIGNMENTS

If Crew-9 launches as scheduled, the crew will include Commander Zena Cardman, Pilot Nick Hague and mission specialist Stephanie Wilson, all from NASA, along with mission specialist Alexsandr Gorbunov, a cosmonaut from Russia’s space agency, Roscosmos. NASA is still considering how to handle staffing at the program level if Crew-9 is reduced from four people to two.

ISS program manager Dana Weigel told Space.com they were not ready to announce the specific crew members for the backup plan yet. She also did not provide details about how this might affect the arrangements with Roscosmos and other space agencies for Crew-9 or future missions when asked. When asked by another reporter about the fate of the two astronauts removed from Crew-9, Weigel said “specific details” were still being worked out. Future flight schedules would be reviewed to see what makes sense for the overall crew lineup going forward.

According to a NASA task order, SpaceX Crew-9 could launch with two astronauts and use mass simulators to fill the two empty seats, regardless of who is on board. Crew-9 would remain docked at the ISS for a typical six-month mission, with Williams and Wilmore returning early next year in the two empty seats.

Weigel highlighted that the CFT astronauts were “fully trained” for a regular ISS rotation, which was planned two years ago with the possibility that a developmental flight could last several months. A normal ISS rotation typically involves astronauts spending about six months on the space station, conducting research and maintaining the station. NASA has spacesuits on board that fit the CFT astronauts, in case they need to perform a spacewalk. The ISS has four months’ supply of such essentials as food and oxygen.

ISS HARMONY MODULE IN HIGH DEMAND

There are other changes occurring in the ISS schedule, as well. Starliner will eventually undock, with or without a crew, to make room for Crew-9 at the ISS Harmony module. The ISS Harmony module is a section of the ISS that acts as a connector for other modules and docking points for visiting spacecraft. It also provides living and working space for the astronauts. Crew-8 will remain on the ISS for about a week after Crew-9 arrives, whenever that may be.

SpaceX has been asked to postpone the launch of its 31st Cargo Dragon mission—a mission of SpaceX’s spacecraft designed to transport supplies and equipment—to the ISS until at least mid-October.

HISTORY OF SETBACKS HAUNTS NASA’S PLAN

SpaceX and Boeing were the two companies chosen by NASA in 2014 to regularly send astronauts to the ISS, following the space shuttle’s retirement in 2011. Russia’s Soyuz spacecraft filled the gap for ISS missions until SpaceX successfully launched its first astronaut test mission in 2020. Unlike Boeing, SpaceX was able to use its Cargo Dragon design as a foundation for developing the Crew Dragon.

Starliner is a completely new spacecraft design and encountered problems during two uncrewed test flights in 2019 and 2022. The first mission failed to reach the ISS due to a computer glitch, while the second reached the ISS but had thruster problems. Teams believed they had resolved the thruster problems from 2022 before approving the CFT launch in 2024.

CHANGES TO ASTRONAUT’S BODY WHEN IN SPACE

1. Space Sickness: In space, such as on the ISS or spacecraft, gravity is much weaker than on Earth. This can cause ‘space sickness’, with such symptoms as headaches, nausea and vomiting. On Earth, gravity affects us strongly and a small organ called the vestibular organ, located in the inner ear, helps us maintain balance.

This organ turns information about gravity and acceleration into electrical signals and sends them to the brain. On Earth, the brain constantly receives gravity information from the vestibular organs, which helps keep body balance.

In space, where gravity is low, the information from the vestibular organs changes, which can confuse the brain and cause space sickness. However, this does not last long. After a few days in space, the brain adapts to the new signals and space sickness goes away.

The severity of space sickness varies from person to person, and some people do not experience it at all. When you return to Earth, you feel the effects of gravity again which can cause ‘gravity sickness’, with symptoms similar to space sickness.

2. Face Often Swells in Space: On Earth, gravity pulls blood and other fluids to the lower body. In space, with weaker gravity, fluids are not pulled down and, instead, collect in the upper body, causing the face to swell. In space, the mucous membranes in the nose also swell, which often causes astronauts to have congested noses. After spending some time in space, the body fluids eventually balance out and facial swelling starts to go away after a few weeks.

In contrast, astronauts often feel dizzy when standing up after returning to Earth, a condition known as orthostatic hypotension. This happens because Earth’s gravity is stronger than in space, making it harder to pump blood from the heart to the head. In space, blood moves more easily, so the heart muscles may weaken, contributing to dizziness when standing. This condition usually improves over time as the body readjusts to Earth’s gravity.

3. Bones and Muscle Weaken: If one spends a long time in space, one’s muscles and bones weaken, especially in the legs and lower back. On Earth, gravity constantly affects a person, so he is always using his lower body muscles, even if he is not aware of it. In space, where gravity is much weaker, a person does not need to stand or use his legs to move around. This lack of use leads to muscle weakening and a decrease in bone mass over time, leading to a loss of strength and endurance. Research is being conducted to test the efficacy of existing drugs in preventing bone loss in astronauts. They also exercise for about two hours a day while on the ISS.

4. Spaceflight’s Viral Threat: Microgravity affects more than just muscles and bones. During the Apollo 7 mission, the three astronauts caught head colds, which are mild illnesses that make you feel stuffy and can cause sneezing and a runny nose. Many astronauts on the ISS have experienced skin rashes and mild respiratory infections. Researchers have also discovered that space travel can reactivate such dormant viruses as herpes simplex, chickenpox and cytomegalovirus (which can cause issues like fever, fatigue and problems with the immune system). These viruses can stay in the body for a long time without causing problems, but can become active again in space.

5. Is Radiation More in Space? In outer space, there is no atmosphere, so radiation is more intense. This intense radiation can have significant effects on the human body.

Earth’s surface is surrounded by an atmosphere, which gives us the oxygen we need to breathe and protects living things from UV rays and radiation. Astronauts in space, where there is little atmosphere, are exposed to more high-energy radiation than on Earth. High exposure to this radiation increases the risk of developing such diseases as cancer.

On the ISS, such hydrogen-rich shielding materials as polyethylene are used in the most frequently occupied areas—the sleeping quarters and galley. This helps reduce the crew’s exposure to space radiation. In space, there is no atmosphere to shield astronauts from UV radiation. Astronauts must protect themselves with spacesuits, helmets with protective visors and space stations.

6. Confined Spaces Cause Stress: The ISS is 357 feet long from end to end—almost the same length as a football field, including its end zones—and offers much more living space than earlier spacecraft, but space for activities is still very limited compared to life on Earth. Astronauts can develop stress without realising it due to living and working in tight quarters with others for months. 

Since the astronauts come from different countries, such as Russia, America, Canada, Europe and Japan, language barriers and cultural differences can also cause stress. To help reduce stress, astronauts can communicate with family and friends while in space and improvements are made to space food.

HOW LONG HAVE PEOPLE LIVED ON THE ISS?

People have been living on the ISS since November 2000. An international crew of seven lives and works on the station, travelling at a speed of five miles/second (8 kilometres/second) and orbiting Earth approximately every 90 minutes. Occasionally, there are more people on board during crew changes.

(The author of this article is a Defence, Aerospace & Political Analyst based in Bengaluru. He is also Director of ADD Engineering Components, India, Pvt. Ltd, a subsidiary of ADD Engineering GmbH, Germany. You can reach him at: girishlinganna@gmail.com)

(Disclaimer: The views expressed above are the author's own and do not reflect those of DNA)